The Experts below are selected from a list of 31581 Experts worldwide ranked by ideXlab platform
Bruce Fischl - One of the best experts on this subject based on the ideXlab platform.
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widespread reductions of Cortical Thickness in schizophrenia and spectrum disorders and evidence of heritability
Archives of General Psychiatry, 2009Co-Authors: Aaron L Goldman, Bruce Fischl, L Pezawas, Venkata S Mattay, Beth A Verchinski, Qiang Chen, Daniel R Weinberger, Andreas MeyerlindenbergAbstract:Context Schizophrenia is a brain disorder with predominantly genetic risk factors, and previous research has identified heritable Cortical and subCortical reductions in local brain volume. To our knowledge, Cortical Thickness, a measure of particular interest in schizophrenia, has not previously been evaluated in terms of its heritability in relationship to risk for schizophrenia. Objective To quantify the distribution and heritability of Cortical Thickness changes in schizophrenia. Design We analyzed a large sample of normal controls, affected patients, and unaffected siblings using a surface-based approach. Cortical Thickness was compared between diagnosis groups on a surfacewide node-by-node basis. Heritability related to disease risk was assessed in regions derived from an automated Cortical parcellation algorithm by calculating the Risch λ. Setting Research hospital. Participants One hundred ninety-six normal controls, 115 affected patients with schizophrenia, and 192 unaffected siblings. Main Outcome Measure Regional Cortical Thickness. Results Node-by-node mapping statistics revealed widespread Thickness reductions in the patient group, most pronouncedly in the frontal lobe and temporal cortex. Unaffected siblings did not significantly differ from normal controls at the chosen conservative threshold. Risch λ analysis revealed widespread evidence for heritability for Cortical Thickness reductions throughout the brain. Conclusions To our knowledge, the present study provides the first evidence of broadly distributed and heritable reductions of Cortical Thickness alterations in schizophrenia. However, since only trend-level reductions of Thickness were observed in siblings, Cortical Thickness per se (at least as measured by this approach) is not a strong intermediate phenotype for schizophrenia.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain poten- tials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy par- ticipants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high ampli- tude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a ampli- tude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relation- ship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive func- tion. Hum Brain Mapp 28:1098-1116, 2007. V V C 2007 Wiley-Liss, Inc.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function.
Anders M. Fjell - One of the best experts on this subject based on the ideXlab platform.
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development and aging of Cortical Thickness correspond to genetic organization patterns
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Stine Kleppe Krogsrud, Lia Ferschmann, Inge K Amlien, Christian K. Tamnes, Darius Adam Rohani, Andreas Berg Storsve, Håkon Grydeland, Anders M. Fjell, Roser SalallonchAbstract:There is a growing realization that early life influences have lasting impact on brain function and structure. Recent research has demonstrated that genetic relationships in adults can be used to parcellate the cortex into regions of maximal shared genetic influence, and a major hypothesis is that genetically programmed neurodevelopmental events cause a lasting impact on the organization of the cerebral cortex observable decades later. Here we tested how developmental and lifespan changes in Cortical Thickness fit the underlying genetic organizational principles of Cortical Thickness in a longitudinal sample of 974 participants between 4.1 and 88.5 y of age with a total of 1,633 scans, including 773 scans from children below 12 y. Genetic clustering of Cortical Thickness was based on an independent dataset of 406 adult twins. Developmental and adult age-related changes in Cortical Thickness followed closely the genetic organization of the cerebral cortex, with change rates varying as a function of genetic similarity between regions. Cortical regions with overlapping genetic architecture showed correlated developmental and adult age change trajectories and vice versa for regions with low genetic overlap. Thus, effects of genes on regional variations in Cortical Thickness in middle age can be traced to regional differences in neurodevelopmental change rates and extrapolated to further adult aging-related Cortical thinning. This finding suggests that genetic factors contribute to Cortical changes through life and calls for a lifespan perspective in research aimed at identifying the genetic and environmental determinants of Cortical development and aging.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain poten- tials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy par- ticipants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high ampli- tude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a ampli- tude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relation- ship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive func- tion. Hum Brain Mapp 28:1098-1116, 2007. V V C 2007 Wiley-Liss, Inc.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function.
Ivar Reinvang - One of the best experts on this subject based on the ideXlab platform.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain poten- tials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy par- ticipants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high ampli- tude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a ampli- tude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relation- ship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive func- tion. Hum Brain Mapp 28:1098-1116, 2007. V V C 2007 Wiley-Liss, Inc.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function.
Kristine B. Walhovd - One of the best experts on this subject based on the ideXlab platform.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain poten- tials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy par- ticipants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high ampli- tude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a ampli- tude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relation- ship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive func- tion. Hum Brain Mapp 28:1098-1116, 2007. V V C 2007 Wiley-Liss, Inc.
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cognitive function p3a p3b brain potentials and Cortical Thickness in aging
Human Brain Mapping, 2007Co-Authors: Anders M. Fjell, Kristine B. Walhovd, Bruce Fischl, Ivar ReinvangAbstract:The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, Cortical Thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire Cortical mantle. In the young, Thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to Cortical Thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that Cortical Thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that Thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional Cortical Thickness and P3 remained. It is concluded that Thickness in specific Cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function.
Alan C. Evans - One of the best experts on this subject based on the ideXlab platform.
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focal decline of Cortical Thickness in alzheimer s disease identified by computational neuroanatomy
Cerebral Cortex, 2005Co-Authors: Jason P Lerch, Jens C Pruessner, Alex P Zijdenbos, Harald Hampel, Stefan J Teipel, Alan C. EvansAbstract:Alzheimer’s disease (AD) is characterized by a heterogeneous distribution of pathological changes throughout the brain. Magnetic resonance imaging can be used to investigate the regional distribution of Cortical atrophy in AD in vivo. One marker for the diseasespecific atrophy is the Thickness of the Cortical mantle across the brain, obtained with automated 3-D image processing. Here, we present data from 36 subjects (17 controls and, 19 patients diagnosed as probable AD) investigated for Cortical Thickness across the entire brain. We show significant Cortical Thickness decline in AD in temporal, orbitofrontal and parietal regions, with the most pronounced changes occurring in the alloCortical region of the medial temporal lobes, outlining the parahippocampal gyrus, and representing a loss of >1.25 millimeters of Cortical Thickness. Moreover, focal Cortical areas decline with progression of the disease as measured by time from baseline scan as well as the Mini-Mental State Exam. The results demonstrate the ability of this method to detect changes in Cortical Thickness in AD, across the entire brain, without need of prior anatomical definitions. The regional distribution of changes reported here is consistent with independent findings on the distribution of neuropathological alterations in AD. Using Cortical Thickness, moreover, we provide a direct quantitative index of atrophy in the disease.
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Cortical Thickness analysis in autism with heat kernel smoothing
NeuroImage, 2005Co-Authors: Moo K Chung, Steven M Robbins, Kim M Dalton, Richard J Davidson, Andrew L Alexander, Alan C. EvansAbstract:We present a novel data smoothing and analysis framework for Cortical Thickness data defined on the brain Cortical manifold. Gaussian kernel smoothing, which weights neighboring observations according to their 3D Euclidean distance, has been widely used in 3D brain images to increase the signal-to-noise ratio. When the observations lie on a convoluted brain surface, however, it is more natural to assign the weights based on the geodesic distance along the surface. We therefore develop a framework for geodesic distance-based kernel smoothing and statistical analysis on the Cortical manifolds. As an illustration, we apply our methods in detecting the regions of abnormal Cortical Thickness in 16 high functioning autistic children via random field based multiple comparison correction that utilizes the new smoothing technique.
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Cortical Thickness analysis examined through power analysis and a population simulation
NeuroImage, 2005Co-Authors: J.p. Lerch, Alan C. EvansAbstract:We have previously developed a procedure for measuring the Thickness of cerebral cortex over the whole brain using 3-D MRI data and a fully automated surface-extraction (ASP) algorithm. This paper examines the precision of this algorithm, its optimal performance parameters, and the sensitivity of the method to subtle, focal changes in Cortical Thickness. The precision of Cortical Thickness measurements was studied using a simulated population study and single subject reproducibility metrics. Cortical Thickness was shown to be a reliable method, reaching a sensitivity (probability of a true-positive) of 0.93. Six different Cortical Thickness metrics were compared. The simplest and most precise method measures the distance between corresponding vertices from the white matter to the gray matter surface. Given two groups of 25 subjects, a 0.6-mm (15%) change in Thickness can be recovered after blurring with a 3-D Gaussian kernel (full-width half max = 30 mm). Smoothing across the 2-D surface manifold also improves precision; in this experiment, the optimal kernel size was 30 mm.
